/* * 8237A DMA controller suspend functions. * * Written by Pierre Ossman, 2005. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. */ #include <linux/init.h> #include <linux/syscore_ops.h> #include <asm/dma.h> /* * This module just handles suspend/resume issues with the * 8237A DMA controller (used for ISA and LPC). * Allocation is handled in kernel/dma.c and normal usage is * in asm/dma.h. */ static void i8237A_resume(void) { unsigned long flags; int i; flags = claim_dma_lock(); dma_outb(0, DMA1_RESET_REG); dma_outb(0, DMA2_RESET_REG); for (i = 0; i < 8; i++) { set_dma_addr(i, 0x000000); /* DMA count is a bit weird so this is not 0 */ set_dma_count(i, 1); } /* Enable cascade DMA or channel 0-3 won't work */ enable_dma(4); release_dma_lock(flags); } static struct syscore_ops i8237_syscore_ops = { .resume = i8237A_resume, }; static int __init i8237A_init_ops(void) { register_syscore_ops(&i8237_syscore_ops); return 0; } device_initcall(i8237A_init_ops); |